Mounted shock sensor

ABSTRACT

This application is directed to a shock sensor mounted in an electronic device. The shock sensor includes both active and passive shock detection methods that allow a technician to determine whether the electronic device was subjected to a shock event that exceeded an impact threshold level. The shock sensor may include shock detection contacts that form an electrical circuit that remains open in the absence of a shock event that exceeds an impact threshold level. In response to a significant shock event, a movable component or substance of the shock sensor may move from a first position to a second position, thereby closing the electrical circuit formed by the shock detection contacts. The change in circuit may be detected and used to provide active indication of whether the electronic device has been subjected to a substantial shock event. In addition, the shock sensor may be observed to passively determine whether the electronic device has been subjected to a substantial shock event.

BACKGROUND OF THE INVENTION

This invention is directed to a shock sensor mounted in an electronicdevice.

Some electronic devices are provided with shock sensors to determine thelevel of shock events to which the electronic device is subjected overthe course of its lifetime. In some cases, the shock sensors may be usedfor warranty purposes (e.g., the warranty is invalid if the electronicdevice is subjected to a shock event that exceeded the shock event of a10 foot drop). Shock sensors can be classified in two categories: activeshock sensors and passive shock sensors.

Active shock sensors can include an accelerometer configured to generatea signal when the accelerometer detects a level of acceleration thatcorresponds to an impact threshold level. The signal may then be read bydetection circuitry without disassembling the electronic device.

An inherent limitation of some active shock sensors, such as those thatinclude accelerometers, is that they require power to operate. Thismeans that they consume power while the device operates, and will notfunction if the device fails (e.g., the device does not power up). Inaddition, adding an active shock sensor may require circuit boardmodifications. Furthermore, if the electronic device is severelydamaged, the active sensor may be rendered inoperable or diagnosticequipment may not be able to obtain data from the sensor or storagemedium containing shock sensing information. Finally, active shocksensors are relatively expensive, at least compared to various passivesensors.

Passive shock sensors typically include an ink capsule that is enclosedin a tube. The capsule is constructed such that it breaks when theelectronic device is subjected to a shock event that exceeds an impactthreshold level. When the capsule ruptures, the ink (or other coloredliquid contained in the capsule) is released and fills the tube. Atechnician may then disassemble the electronic device and observe theshock sensor to determine, based on the location the ink in the shocksensor, whether the electronic device was subjected to a shock eventthat exceeded the impact threshold level.

While passive shock sensors do not exhibit some of the limitations ofactive shock sensors, they are generally not resettable. This requiresthe shock sensor to be replaced when the electronic device is repairedor refurbished. In addition, there is typically no method for observingthe shock sensor from the outside of the electronic device. Instead, thetechnician must disassemble the device to access the shock sensor.

Accordingly, it would be desirable to provide a shock sensor thatexhibits both active and passive attributes. In particular, it would bedesirable to provide a shock sensor that can be analyzed withoutdisassembling the device. It would also be desirable to provide a shocksensor that can be analyzed when the device has failed and electronicdetection is not possible.

SUMMARY OF THE INVENTION

A shock sensor by which shock events can be analyzed withoutdisassembling the device is provided. A shock sensor by which shockevents can be analyzed when the device has failed is also provided. Theshock sensor provides both active and passive attributes for atechnician to analyze the shock events endured by an electronic device.

In accordance with some embodiments of the invention, a shock sensorthat includes shock detection circuitry is provided. The shock detectioncircuitry may include one or more shock detection contacts (e.g., awire) that may be electrically coupled to the shock sensor such that inthe absence of a significant enough shock event, no signal is providedto indicate the occurrence of a shock event. Signal detection can beperformed by a diagnostic device that interfaces (e.g., connects to adocking port) with the assembled electronic device so that a techniciancan check the shock event status without disassembling the electronicdevice.

Different mechanisms may be used to provide an electrical signal inresponse to a shock event that exceeds the impact threshold level.Generally, a movable component or substance may be configured to movefrom a first position in which the shock detection contacts form an openelectrical circuit to a second position in which the movable componentor substance closes the electrical circuit formed by the shock detectioncontacts to provide an electrical signal.

In one embodiment, shock detection contacts may be inserted in a chamberat a predetermined distance from each other. A reservoir (e.g., similarto an ink capsule) containing a conductive fluid can be enclosed withinthe chamber. When a shock event exceeds the impact threshold level, thereservoir may rupture and release the conductive fluid in the chamber.The conductive fluid may then short the shock detection contactsextending into the chamber. Detection circuitry may provide anelectrical signal in response to the short circuit.

In some embodiments, the conductive fluid may also serve as a passiveshock sensor. If a diagnostic device is not able to detect an electricalsignal, the electronic device may be disassembled to observe the shocksensor. If the conductive fluid is in the chamber and not restrained inthe reservoir, the shock sensor passively indicates whether a shockevent was experienced that exceeded the impact threshold level. Theconductive fluid may be colored to allow easier passive shock detection.

In another embodiment, a cantilever spring may be electrically coupledto a first shock detection contact. A second shock detection contact maybe electrically coupled to a chamber that encloses the free end of thecantilever spring (e.g., a tube or an open box). In response to a shockevent that exceeds the impact threshold level, the cantilever springbends, and the free end of the cantilever spring comes into contact withthe chamber and shorts the first and second shock detection contacts.

The free end of the cantilever spring may include a magnet, and thechamber may be constructed from magnetically reactive material such thatwhen a shock event exceeds the impact threshold level, the magnet of thecantilever comes into and remains in contact with the chamber bymagnetic attraction, thereby closing the electrical circuit. Theposition of the cantilever and magnet provides a method for passivelydetermining whether a shock event on the electronic device exceeded thethreshold. A technician can disassemble the electronic device andobserve the location of the magnet within the chamber. If the magnet isin contact with the chamber, the shock sensor passively indicates ashock event that exceeded the impact threshold level.

The shock sensor can be reset using a tool to decouple the magnet fromthe chamber. Once the magnet is returned to an equilibrium positionbetween the walls of the chamber, and the effect of the electricalsignal removed (e.g., reset a bit in memory), the shock sensor can bere-used in the electronic device.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features of the present invention, its nature andvarious advantages will be more apparent upon consideration of thefollowing detailed description, taken in conjunction with theaccompanying drawings in which:

FIG. 1 is a schematic view of an illustrative shock sensor system thatincludes both active and passive attributes in accordance with oneembodiment of the present invention;

FIG. 2 is a schematic view of an illustrative device in which a shocksensor is implemented in accordance with one embodiment of the presentinvention;

FIG. 3A is a simplified cross-sectional view of an illustrative shocksensor system that includes both active and passive attributes inaccordance with one embodiment of the present invention;

FIG. 3B is a simplified cross-sectional view of the illustrative shocksensor system of FIG. 3A when the electronic device in which the shockevent system is implemented is subjected to a shock event that exceededthe impact threshold level of the sensor in accordance with oneembodiment of the present invention;

FIG. 4A is a simplified cross-sectional view of another illustrativeshock sensor system that incorporates both active and passive attributesin accordance with one embodiment of the present invention;

FIG. 4B is a simplified cross-sectional view of the shock sensor systemof FIG. 4A when the sensor has been subjected to a shock event thatexceeded the impact threshold level in accordance with one embodiment ofthe present invention;

FIG. 4C is a simplified cross-sectional view of another configurationfor the illustrative shock sensor system of FIG. 4A in accordance withone embodiment of the present invention;

FIG. 5 is a perspective view of a resetting tool for the shock sensorsystem of FIGS. 4A and 4B in accordance with one embodiment of thepresent invention;

FIG. 6 shows an illustrative flow chart for actively and passivelyindicating the occurrence of a shock event in accordance with oneembodiment of the present invention; and

FIG. 7 shows an illustrative flow chart of a process for determiningwhether an electronic device in which a shock sensor system has beenimplemented has been subjected to a shock event that exceeded the impactthreshold level for the device in accordance with one embodiment of thepresent invention.

DETAILED DESCRIPTION

In accordance with the present invention, a shock sensor that exhibitattributes of both active shock sensors and passive shock sensors isprovided.

FIG. 1 is a schematic view of an illustrative shock sensor that includesboth active and passive attributes. Shock sensor 100 may include shockdetection circuitry 102 configured to provide an electrical signal whenthe shock sensor is subjected to a shock event that exceeds the impactthreshold level of the shock sensor. Shock detection circuitry 102 maybe electrically coupled to one or more shock detection contacts 104 byconductive connection 106. Shock detection contacts 104 may include, forexample, a wire, a conductive plate, a conductive region, or any othersuitable contact. Conductive connection 106 can include any suitableconnection that conducts electricity between shock detection circuitry102 and shock detection contacts 104 (e.g., a wire).

Shock detection contacts 104 and shock detection circuitry 102 may beconfigured to form an electrical circuit that is open in the absence ofa shock event that exceeds the impact threshold level of shock sensor100. So long as the electrical circuit remains open, shock detectioncircuitry may be configured not to provide an electrical signal (or atleast a signal that does not indicate that the impact threshold has beenexceeded). For example, shock detection contacts 104 may include atleast two wires that are maintained at a distance from each otherwithout an electrical coupling. When shock sensor 100 is subjected to asufficiently large shock event, the state of shock sensor 100 may bechanged such that the wires become electrically coupled and theelectrical circuit formed by shock detection contacts 104 and shockdetection circuitry 102 may be closed.

Shock sensor 100 may include movable component or substance 108. Movablecomponent or substance 108 may be configured to move from a firstposition to a second position in response to a shock event that exceedsthe impact threshold level of shock sensor 100. In the first position,movable component or substance 108 may be configured to maintainelectrical isolation between shock detection contacts 104. In the secondposition, movable component or substance 108 may be configured to shortshock detection contacts 104 such that the electrical circuit formed byshock detection contacts 104 and shock detection circuitry 102 may beclosed. In addition, the first and second positions of movable componentor substance 108 may be observably different such that a technician,observing shock sensor 100, may identify the position of movablecomponent or substance 108 and passively detect shock events. The impactthreshold level of shock sensor 100 may be determined by the level ofthe shock event necessary to cause movable component or substance 108 tomove from the first position to the second position.

In response to a shock event that causes movable component or substance108 to short shock detection contacts 104, shock detection circuitry 102detects the short circuit. In response to detecting the short circuit,shock detection circuitry 102 may be configured to provide an electricalsignal identifying the shock event. In some embodiments, shock detectioncircuitry 102 may continuously or intermittently provide an electricalsignal available for detection. In some embodiments, shock detectioncircuitry 102 may provide an electrical signal that causes the state ofshock sensor 100 to be modified. For example, the electrical signal maycause one or more bits in memory of shock detection circuitry 102, or inanother component of shock sensor 100 (e.g., an RFID tag) to change. Insome embodiments, shock detection circuitry 102 may provide anelectrical signal that causes the state of the electronic device inwhich shock sensor 100 is implemented to be modified. For example, theelectrical signal may cause one or more bits in the memory of theelectronic device to be modified. Shock sensor 100 may use one or moreof these approaches (e.g., transmit a signal at different intervalsbased on the state change of shock sensor 100 or of the electronicdevice).

Detection circuitry 102 may be configured to detect momentary shortcircuits. Based on the duration of the short circuit, detectioncircuitry 102 may ignore or process the short circuit. For example, ashort circuit that is detected for a very short duration may beprocessed as a short circuit that occurred because the device wassubjected to a substantial shock event and immediately failed. Asanother example, a short circuit that is detected for a longer durationmay be processed as a false positive caused by a temporary displacementof movable component or substance 108 from the first position to thesecond position. The windows for interpreting the duration of shortcircuits may be selected in any suitable manner, for example usingempirical data. In some embodiments, shock detection circuitry 102 mayinterface with a processor of the electronic device before interpretinga short circuit (e.g., to determine whether the electronic device hasfailed).

In some embodiments, shock detection circuitry 102 may be incorporatedin the electronic device in which shock sensor 100 is implemented. Forexample, shock detection circuitry 102 may be incorporated in theprocessor of the electronic device. In such embodiments, the electricalsignal provided by shock detection circuitry 102 may be configured tomodify the state of the electronic device instead of the state of shocksensor 100.

Shock sensor 100 may be electrically coupled to the electronic device inany suitable manner. In some embodiments, shock sensor 100 may besoldered to a circuit board of the electronic device in which shocksensor 100 is implemented. Soldering shock sensor 100 directly to thecircuit board provides an easy, repeatable, and reliable method forcoupling shock sensor 100 to the circuit board. Effectively, the shocksensor may simply become another element that is assembled to theelectronic device's circuit board. In some embodiments, shock detectioncircuitry 102, shock detection contacts 104, or both may be soldered toa circuit board of the electronic device.

To determine whether shock sensor 100 was subject to a shock event eventhat exceeded the impact threshold level, a technician may use twoapproaches. A first approach may be to detect the electrical signalprovided by shock detection circuitry 102 or to detect the effect of theelectrical signal provided by shock detection circuitry 102. To detectthe electronic signal or the electronic signal's effect, a technicianmay use diagnostic device 110. For example, in embodiments in whichshock detection circuitry 102 continually transmits an electricalsignal, the technician may couple diagnostic device 110 to shockdetection circuitry 102 and detect the impedance, voltage, or currentprovided by detection circuitry 102. As another example, if theelectronic signal modified the state of shock sensor 100 or of theelectronic device, the diagnostic device may be configured to identifythe state variable of shock sensor 100 or of the electronic device.Based on the value of the state variable, diagnostic device 110 maydetermine whether shock sensor 100 was subject to a shock event thatexceeded the impact threshold level.

In some embodiments, the electronic device, shock sensor 100, or bothmay fail and prevent diagnostic device 110 from determining whether anelectronic signal was provided by shock detection circuitry 102. Forexample, if shock sensor 100 does not have power, diagnostic device 110cannot determine whether shock detection circuitry 102 wouldcontinuously transmit an electronic signal if power were available. Asanother example, if a shock event caused a complete failure of theelectronic device, diagnostic device 110 cannot determine whether shockdetection circuitry 102 attempted to modify the state of shock sensor100 or of the electronic device.

When diagnostic device 110 cannot provide a conclusive answer as towhether shock sensor 100 endured a shock event exceeding the impactthreshold level, the technician may observe movable component orsubstance 108. In some embodiments, the technician may be required todisassemble the electronic device in order to view shock sensor 100 andmovable component or substance 108. If the technician observes thatmovable component or substance 108 is in the second position, thetechnician may conclude that shock sensor 100 was subject to a shockevent that exceeded the impact threshold level. If instead, thetechnician observes that movable component or substance 108 is in thefirst position, the technician may conclude that shock sensor 100 wasnot subject to a shock event exceeding the impact threshold level.

In some embodiments, after determining that shock sensor 100 was subjectto a shock event that exceeded the impact threshold level, and thus thatmovable component or substance 108 moved from the first position to thesecond position, the technician may reset shock sensor 100. To resetshock sensor 100, the technician may return movable component orsubstance 108 to the first position. In addition, the technician mayreset the state of shock sensor 100 and of the electronic device, ifnecessary (e.g., reset one or more bits in memory). The technician mayalso reset shock detection circuitry 102 so that it does not provide acontinuous electrical signal (indicating the occurrence of a shock eventthat exceeded the impact threshold level).

FIG. 2 shows a simplified block diagram of illustrative portableelectronic device 200 in which a shock sensor is implemented. Electronicdevice 200 may include processor 202, storage device 204, user interface208, display 210, CODEC 212, shock sensor 216, bus 218, memory 220,communications circuitry 222, and shock detection circuitry 223.Processor 202 can control the operation of many functions and othercircuitry included in electronic device 200. Processor 202 may drivedisplay 210 and may receive user inputs from user interface 208.

Storage device 204 may store media (e.g., music and video files),software (e.g., for implementing functions on device 200, preferenceinformation (e.g., media playback preferences), lifestyle information(e.g., food preferences), exercise information (e.g., informationobtained by exercise monitoring equipment), transaction information(e.g., information such as credit card information), wireless connectioninformation (e.g., information that may enable device to establish awireless connection such as a telephone connection), subscriptioninformation (e.g., information that keeps tracks of podcasts ortelevision shows or other media a user subscribes to), telephoneinformation (e.g., telephone numbers), shock event information (e.g., ahistory of shock events that exceed an impact threshold level), and anyother suitable data. Storage device 204 may include one more storagemediums, including for example, a hard-drive, permanent memory such asROM, semi-permanent memory such as RAM, or cache.

Memory 220 may include one or more different types of memory which maybe used for performing device functions. For example, memory 220 mayinclude cache, Flash, ROM, and/or RAM. Memory may be specificallydedicated to storing firmware. For example, memory may be provided forstore firmware for device applications (e.g., operating system, userinterface functions, and processor functions).

Shock sensor 216 may be provided for detecting shock events to whichdevice 200 is subject in accordance with an embodiment of the presentinvention. Shock sensor 216 may communicate with other circuitry indevice 200 directly (not shown in this FIG.) or indirectly via bus 218.

Shock detection circuitry 223 may be provided to monitor shock sensor216. Shock detection circuitry 223 may be configured, in response todetermining that shock sensor 216 was subject to a substantial shockevent, to provide an electrical signal to processor 202, directing theprocessor to change the state of shock system 216 or device 200 (e.g.,change one or more bits in storage 204 or memory 220). In someembodiments, shock detection circuitry may be configured to provide anelectrical signal continuously or at least various intervals.

Bus 218 may provide a data transfer path for transferring data to, from,or between storage device 204, shock sensor 216, shock detectioncircuitry 213, communications circuitry 222, memory 220, and processor202. Coder/decoder (CODEC) 212 may be included to convert digital audiosignals into an analog signal, which may be provided to an output port(not shown).

Communications circuitry 222 may be included in a carrier circuitryportion (delimited by dashed lines 225) of device 200. Carrier circuitryportion 225 may be dedicated primarily to processing telephone functionsand other wireless communications (e.g., Wi-Fi or Bluetooth). It isunderstood that the carrier circuitry portion operate independent ofother device components operating in device 200. That is, carriercircuitry may be an independently operating subsystem within device 200that may communicate with other components within device 200.

User interface 208 may allow a user to interact with the device 200. Forexample, the user input device 208 can take a variety of forms, such asa button, keypad, dial, a click wheel, or a touch screen. Communicationscircuitry 222 may include circuitry for wireless communication (e.g.,short-range and/or long range communication). For example, the wirelesscommunication circuitry may be Wi-Fi enabling circuitry that permitswireless communication according to one of the 802.11 standards or aprivate network. Other wireless network protocols standards could alsobe used, either in alternative to the identified protocols or inaddition to the identified protocol. Another network standard may beBluetooth.

Communications circuitry 222 may also include circuitry that enablesdevice 200 to be electrically coupled to another device (e.g., acomputer or an accessory device) and communicate with that other device.As indicated above, communications circuitry 222 may also includebaseband circuitry for performing relatively long-range communications(e.g., telephone communications). If desired, communications circuitry222 may include circuitry for supporting both relatively long-range andshort-range communications. For example, communications circuitry 222may support telephone, Wi-Fi, and Bluetooth communications.

In one embodiment, device 200 may be a portable computing devicededicated to processing media, such as audio and video. For example,device 200 may be a media player (e.g., MP3 player), a game player, aremote controller, a portable communication device, a remote orderinginterface, an audio tour player, or other suitable personal device. Inanother embodiment, device 200 may be a portable device dedicated toproviding media processing and telephone functionality in a singleintegrated unit. Device 200 may be battery-operated and highly portableso as to allow a user to listen to music, play games or video, recordvideo or take pictures, place and take telephone calls, communicate withothers, control other devices, and any combination thereof. In addition,device 200 may be sized such that it fits relatively easily into apocket or hand of the user. By being handheld, device 200 is relativelysmall and easily handled and utilized by its user and thus may be takenpractically anywhere the user travels.

FIGS. 3A, 3B, 4A and 4B describe illustrative shock sensors that includeshock detection contacts and a movable component or substance that canbe moved from a first position to a second position. These illustrativeshock sensors will be described in more detail in the followingdiscussion.

FIG. 3A is a simplified cross-sectional view of an illustrative shocksensor system that includes both active and passive attributes. Sensor300 includes chamber 302 that may be mounted in an electronic device(not shown). Contacts 304 and 306 extend inside chamber 302 and may besoldered to a circuit board of the electronic device (e.g., a flex boardor a rigid board). Contacts 304 and 306 are separated such that, in theabsence of a conductor between contacts 304 and 306, the electricalcircuit formed by contacts 304 and 306 is OPEN.

Chamber 302 may be constructed from any suitable material including, forexample, glass, plastic and composite materials. Chamber 302 can betransparent or translucent to permit an operator to view the locationand color of fluid in the chamber (e.g., to passively determine whetherchamber 302 was subjected to a shock event that exceeded the impactthreshold level). To prevent liquid from leaving chamber 302 through thechamber wall at the location where contacts 304 and 306 extend into thechamber, chamber 302 may be constructed such that contacts 304 and 306are inserted into the chamber wall when portions of the chamber areselectively melted. For example, chamber 302 may be heated to a viscousstate and contacts 304 and 306 (e.g., the tips of exposed wires) may beinserted through the viscous chamber wall. When chamber 302 is cooledand becomes solid, contacts 304 and 306 extend securely through thechamber wall.

Contacts 304 and 306 may be any suitable conductive material. Forexample, contacts 304 and 306 may be constructed from copper, silver,gold, aluminum, nickel, lead, graphite, or any other suitable conductor.Contacts 304 and 306 can be soldered to the circuit board using flux toprevent the formation of metal oxides and to enhance wetting. Fluid 312of shock sensor 300 (discussed in more detail below) can be selectedsuch that it does not boil at soldering temperatures (e.g., so that itdoes not boil and cause reservoir 310 or membrane 314 to rupture whencontacts 304 and 306 are electrically coupled to a circuit board).

Chamber 302 includes reservoir 310 enclosed within chamber 302 (e.g.,attached to the inner surface of chamber 302 at one end of the chamber).Reservoir 310 may at least partially be filled with conductive fluid312. Fluid 312 may be maintained within reservoir 310 by membrane 314,which may be coupled to tip 311 of chamber 310. Membrane 314 may beconstructed to rupture in response to a shock event that exceeded theimpact threshold level of shock sensor 300.

In some embodiments, reservoir 310 may be incorporated in chamber 302such that membrane 314 separates chamber 302 into two sections. Membrane314 may be coupled to reservoir 310 or to chamber 302 in any suitablemanner. For example, an adhesive may be used to attach membrane 314 toreservoir 310. The adhesive may be selected such that it releasesmembrane 314 when the shock event on the electronic device exceeds theimpact threshold level. As another example, membrane 314 may bemanufactured as part of reservoir 310 (e.g., molded in the reservoir).

In some embodiments, reservoir 310 can be configured to rupture when theelectronic device receives a shock event that exceeds the impactthreshold level. In such embodiments, entire reservoir 310 can beconstructed as membrane 314. Reservoir 310 and membrane 314 may beformed from any suitable material such that reservoir 310 and membrane314 are weaker, and therefore will break or separate before chamber 302breaks. Such materials may include, for example, glass, plastic,composite materials, or any other such materials.

FIG. 3B is a simplified cross-sectional view of the illustrative shocksensor system of FIG. 3A when the electronic device in which the shockevent system is implemented is subjected to a shock event that exceededthe impact threshold level of the sensor. When the electronic device issubjected to such a shock event, conductive fluid 312 escapes fromreservoir 310 and fills chamber 302. Because conductive fluid 312 isconductive, it closes the electrical circuit between contacts 304 and306, resulting in transmission of a different electrical signal todetection circuitry.

Membrane 314, reservoir 310, or both may break or separate to allowconductive fluid 312 to fill chamber 310. In the example shown in FIG.3B, membrane 314 ruptured, and is no longer shown in FIG. 3B. Conductivefluid 312 may be colored such that it may be clearly visible withinreservoir 310 or chamber 302.

To set the impact threshold level at which shock sensor 300 allowsconductive fluid 312 to short contacts 304 and 306, a number ofparameters may be adjusted. These parameters include, for example, thedensity and volume of conductive fluid 312 in reservoir 310, thediameter of reservoir 310, the strength of membrane 314, the manner inwhich membrane 314 may be coupled to reservoir 310, the wall thicknessof reservoir 310, or any other suitable parameter.

With shock sensor 300, there are two methods for determining whether theelectronic device in which the shock sensor was implemented wassubjected to a shock event that exceeded the impact threshold level.First, when conductive fluid 312 fills chamber 302, the electricalcircuit between contacts 304 and 306 may be closed and an electricalsignal may be provided. The electrical signal may be received oridentified by a suitable diagnostic device.

If the electronic device is so damaged that it is not able to transmitan electronic signal indicative of shock event status, shock sensor 300provides passive shock detection for determining whether the electronicdevice was subjected to a shock event or impact that exceeded the impactthreshold level. In some embodiments, the electronic device may need tobe opened to observe chamber 302 to determine whether conductive fluid312 is visible within entire chamber 302 (indicating that shock sensor300 was subjected to a shock event that exceeded the impact thresholdlevel).

It should be understood that detection of a passive attribute of theshock sensor need not always require that the electronic device beopened or disassembled. In some embodiments, the electronic device mayinclude a transparent part that permits a technician to see chamber 302.In some embodiments, a passive RFID tag may be electrically coupled tocontacts 304 and 306. The RFID tag may provide a signal when contacts304 and 306 are shorted together by, for example, conductive fluid 312.When contacts 304 and 306 are shorted, this short circuit may close acircuit connecting in the RFID tag, thereby enabling the RFID tag toemit a signal (which may indicate that the electronic device has beensubject to a shock event that exceeds the impact threshold level) inresponse to receiving a signal from a RFID detection device. If the RFIDdetection device does not receive a signal from the RFID tag, this mayindicate that the electronic device has not been subject to an excessiveshock event. An advantage of using a passive RFID tag may be that itdoes not require a power source to operate, as it receives power in thesignal provided by the RFID detection device. If desired, active RFIDtags may be used in lieu of passive RFID tags. It is understood thatRFID tags may be used for any shock sensor embodiment described herein.

FIG. 4A is a simplified cross-sectional view of another illustrativeshock sensor system that incorporates both active and passiveattributes. Shock sensor 400 includes chamber 402 and spring 404.Chamber 402 encloses spring 404 in at least two directions (e.g., up anddown, as shown in FIG. 4A). Chamber 402 can be a tubular structure, arectangular structure (e.g., similar to box 102 of FIG. 1), or any othersuitable structure for disposing spring 404 within the structure. Insome embodiments, as shown in FIG. 4C, chamber 402 may be coupled to thefixed end of spring 404 at contact point 405 (e.g., the open end ofchamber 402 is by the free end of spring 404, and not by the fixed end).

Chamber 402 may be constructed from any suitable material. Inparticular, chamber 402 may be constructed from an electricallyconducting material to transmit electrical signals when shock sensor 400is subjected to a shock event that exceeded the impact threshold level.Chamber 402 may also be constructed from a material that has magneticproperties. For chamber 402 to exhibit both of these properties, chamber402 may be constructed from, for example, steel, iron, iron basedalloys, or any other material that may be both electrically conductiveand magnetic. Other suitable materials may include permanent magnets andelectro-magnets.

Spring 404 may be a cantilever spring that may be fixed to shock sensor400 (or to the electronic device in which shock sensor 400 isimplemented) at contact point 405. Contact point 405 may be a point ofplate 406 that may be fixed with respect to chamber 402. In someembodiments, contact point 405 may be on chamber 402 (e.g., if chamber402 extends where plate 406 is shown in FIG. 4A). At its restingposition, spring 404 may be configured to be equidistant from eachsection of chamber 402. In some embodiments, spring 404 and plate 406may be constructed from electrically conductive material.

Magnet 410 may be coupled to the free tip of spring 404. Magnet 410 maybe any suitable magnet, for example a permanent magnet. Magnet 410 maybe constructed in any suitable shape. In the example of FIG. 4A, magnet410 may be spherical. Other suitable shapes may include, for example,cylindrical, polyhedral, trapezoidal, or rectangular.

The polarity of magnet 410 and chamber 402 may be configured such thatmagnet 410 may be attracted to chamber 402. For example, top portion 411of magnet 410 may be a north pole, and upper wall 412 may be a southpole such that top portion 411 may be magnetically attracted to upperwall 412. Similarly, bottom portion 413 of magnet 411 may be a southpole, and lower wall 414 may be a north pole such that bottom portion413 may be magnetically attracted to lower wall 414. The strength of themagnetic attraction between walls 412 and 414 and the portions of magnet410 may be configured such that magnet 410 remains in an equilibriumposition at equal distances from each of upper and lower walls 412 and414, respectively.

Shock sensor 400 includes shock detection circuitry 420 for transmittinga signal when shock sensor 400 is subjected to a shock event thatexceeded the impact threshold level. Circuitry 420 may be electricallycoupled to chamber 402 and to plate 406 by paths 422 and 424,respectively. When the circuit between paths 422 and 424 is closed, anelectrical signal or a change in a state may be detected by shockdetection circuitry 420. Detection circuitry 420 may register or storethe occurrence of an excessive shock event so that such information canbe provided, for example, to a diagnostic device. In the embodiment ofFIG. 4C, circuitry 420 may be electrically coupled by paths 422 and 424to different portions of chamber 402 that are electrically insulatedfrom each other.

In some embodiments, detection circuitry 420 may transmit an electricalsignal continuously or at various intervals in response to determiningthat the circuit between paths 422 and 424 has been closed. In someembodiments, detection circuitry 420 may change the state of shocksensor 400, for example by changing one or more bits in the memory ofdetection circuitry 420. In some embodiments, detection circuitry 420may change the state of the electronic device, for example by changingone or more bits in the memory of the electronic device.

When shock sensor 400 is subjected to a shock event that exceeds theimpact threshold level, spring 404 bends and magnet 410 comes intocontact with chamber 402. FIG. 4B is a simplified cross-sectional viewof the shock sensor system of FIG. 4A when the sensor has been subjectedto a shock event that exceeds the impact threshold level.

When bottom magnet 410 comes into contact with chamber 402, theelectrical circuit formed by paths 422 and 424 may be closed, and anelectrical signal may be transmitted to detection circuitry 420. Theelectrical signal can be transmitted because all of plate 406, spring404, magnet 410 and chamber 402 are constructed from electricallyconductive materials.

In addition, because bottom portion 413 and lower wall 414 are subjectto a magnetic attraction force, magnet 410 remains in contact withchamber 402 after the shock event has dissipated. An external force maybe required to release magnet 410 from chamber 402.

The impact threshold level for shock sensor 400 depends on a number ofparameters. These parameters include the distance between chamber 402and magnet 410, the magnetic permeability and magnetic strength ofmagnet 410 and chamber 402, the spring constant of spring 404, thelength of spring 404, the mass of magnet 410, and any other suitableparameter. These parameters may be chosen to define a particular impactthreshold level.

With shock sensor 400, there are two methods for determining whether theelectronic device in which the shock sensor was implemented wassubjected to a shock event that exceeded the impact threshold level.First, when magnet 410 comes into contact with chamber 402, theelectrical circuit formed by paths 422 and 424 may be closed, providingan electrical signal that can be received by detection circuitry 420.The electrical signal can then be identified or measured, thus providingthe functionality of an active shock sensor.

In addition, shock sensor 400 also exhibits the functionality of apassive shock sensor. If the electronic device is so damaged that ashock event signal is not capable of being read by diagnostic equipment,shock sensor 400 may be observed to determine the location of magnet 410within chamber 402. In particular, if magnet 410 is in contact withchamber 402, it indicates that shock sensor 400, and therefore theelectronic device in which it is implemented, was subjected to a shockevent that exceeded the impact threshold level and caused magnet 410 tobend spring 404 so far that magnet 410 came into contact with chamber402. In some embodiments, a technician may be required to at least inpart disassemble the electronic device to view shock sensor 400.

Unlike many purely passive shock sensors, shock sensor 400 may be not asingle use sensor. Instead, shock sensor 400 may be reset within theelectronic device by returning magnet 410 to its equilibrium positionaway from chamber 402 and by resetting the state of the electronicdevice (e.g., resetting the bit in memory that was modified to indicatea shock event that exceeded the impact threshold level).

To reset magnet 410, the technician may use an appropriate tool. FIG. 5is a perspective view of a resetting tool for the shock sensor system ofFIGS. 4A and 4B. Tool 500 may be a U-shaped device that may beconfigured to fit between chamber 402 and spring 404 (FIG. 4B). Tool 500includes points 502 and 504 that may be configured to slide betweenmagnet 410 and chamber 402 such that point 502 or 504 separates magnet410 from chamber 402. Tool 500 may have any suitable thickness 506. Insome embodiments, thickness 506 may be selected such that magnet 410 maybe released from the magnetic attraction of chamber 402 when magnet 410is at a distance 506 from the wall.

Tool 500 may be constructed from non-magnetic material to avoidundesired interactions with chamber 402 or magnet 410. A technician mayinsert tool 500 into shock sensor 400 in any suitable manner. Forexample, chamber 402 may include a aperture configured to receive points502 and 504. As another example, tool 500 may be inserted in the spacebetween chamber 402 and plate 406.

FIG. 6 shows an illustrative flow chart for actively and passivelyindicating the occurrence of a shock event. Process 600 begins at step602. At step 604, the movable component or substance of a shock sensormoves from a first position to a second position. For example, themovable component or substance may move to a second position in responseto a shock event that exceeds an impact threshold level of the shocksensor. The movable component or substance may include, for example,conductive fluid retained within a chamber, or a cantilever spring witha magnet enclosed by a chamber.

At step 606, detection circuitry of the shock sensor provides anelectrical signal. For example, the detection circuitry may monitor themovable component or substance, and provide an electrical signal inresponse to the movable component or substance moving to the secondposition. In some embodiments, the detection circuitry may monitor shockdetection contacts that are configured to be short circuited by themovable component or substance when it is in the second position. Theelectrical signal may be continuously or intermittently provided fordetection by a diagnosis device. Alternatively or in addition, theelectrical signal may cause the shock sensor or an electronic device inwhich the shock sensor is implemented to change its state (e.g., changeone or more bits in memory). The diagnosis device may then be configuredto detect the change in state. The electrical signal or of its effectmay be used to actively detect the occurrence of shock events.

At step 608, a technician observes the movable component or substance.For example, the technician may observe whether the movable component orsubstance is in the second position, passively indicating the occurrenceof a shock event. The movable component or substance may be configuredto remain in the second position after a substantial shock event toprovide passive detection of shock events. In some embodiments, thetechnician may be required to disassemble the electronic device in whichthe shock sensor is implemented to observe the movable component orsubstance. Process 600 then ends at step 610.

FIG. 7 shows an illustrative flow chart of a process for determiningwhether an electronic device in which a shock sensor system has beenimplemented has been subjected to a shock event that exceeded the impactthreshold level for the device. Process 700 begins at step 702. At step704, a technician connects a diagnostic device to an electronic deviceincluding an active/passive shock sensor according to an embodiment ofthe invention. The diagnostic device may check paths 302 and 304 (FIG.3A) or paths 420 and 422 (FIG. 4A). At step 706, the diagnostic devicedetermines whether an electrical signal indicating that a shock eventexceeding the impact threshold level is present. For example, thediagnostic device may detect an electrical signal or the detectioncircuitry may identify a change of state of the electronic device (e.g.,a bit changed in memory). The electrical signal may be transmittedbecause a movable component or substance of the shock sensor closed theelectrical circuit between the shock sensor cables. This is anexamination of the active feature of the shock sensor. If the detectioncircuitry detects an electrical signal, process 700 moves to step 708.

At step 708, the technician determines, based on the presence of theelectrical signal, that the electronic device was subjected to a shockevent that exceeded the impact threshold level. Process 700 then ends atstep 710.

If, at step 706, the detection circuitry instead does not detect anelectrical signal, process 700 moves to step 712. At step 712, thetechnician determines whether the electronic device is too badly damagedto provide active shock detection. For example, the technician maydetermine whether the device powers up. As another example, thetechnician may determine whether individual components of the electronicdevice are operating when provided with power. If the techniciandetermines that the electronic device is not too badly damaged toprovide active shock detection, process 700 moves to step 714.

At step 714, the technician determines, based on the absence of theelectrical signal and on the powering up of the electronic device, thatthe electronic device was not subjected to a shock event that exceededthe impact threshold level. Process 700 then ends at step 716.

If, at step 712, the technician instead determines that the electronicdevice is too badly damaged to provide active shock detection, process700 moves to step 718. At step 718, the technician opens the electronicdevice to examine the shock sensor. This is an examination of thepassive aspect of the shock sensor. At step 720, the techniciandetermines whether the shock sensor passively indicates that theelectronic device was subjected to a shock event that exceeded theimpact threshold level. To do so, the technician may determine whether amovable component or substance of the shock sensor moved from a firstposition to a second position. For example, the technician may determinewhether fluid 312 is present in chamber 302 (FIG. 3B). As anotherexample, the technician may determine whether magnet 410 is in contactwith chamber 402 (FIG. 4B). If the technician determines that the shocksensor does not passively indicate that the electronic device wassubjected to an exceedingly high shock event, process 700 moves to step714.

If, at step 720, the technician instead determines that the shock sensorpassively indicates that the electronic device was subjected to anexceeding shock event, process 700 moves to step 708. In someembodiments, after step 708, process 700 may include a step forresetting the shock sensor. For example, the technician may returnmagnet 410 to its equilibrium position away from chamber 402 (FIGS. 4A,5). Process 700 then ends.

The above described embodiments of the present invention are presentedfor purposes of illustration and not of limitation, and the presentinvention is limited only by the claims which follow.

1. A shock sensor that actively and passively indicates the occurrenceof a shock event, comprising: at least one shock detection contactcoupled to shock detection circuitry to form an open electrical circuit;and a movable component or substance operative to move from a firstposition to a second position wherein, in response to a shock event, themovable component or substance moves to the second position and shortsthe electrical circuit to provide active shock detection and is observedin the second position to provide passive shock detection.
 2. The shocksensor of claim 1, wherein the shock detection circuitry provides anelectrical signal in response to shorting the electrical circuit.
 3. Theshock sensor of claim 2, wherein the electrical signal changes the stateof the shock sensor.
 4. The shock sensor of claim 1, wherein the movablecomponent or substance remains in the second position in response to theshock event.
 5. The shock sensor of claim 1, wherein the shock eventexceeds an impact threshold level for the shock sensor.
 6. The shocksensor of claim 1, further comprising an RFID tag that is renderedoperable to emit a signal when the movable component or substance movesto the second position.
 7. The shock sensor of claim 1, wherein themovable component or substance comprises a chamber and a reservoirenclosed within the chamber.
 8. The shock sensor of claim 7, wherein:conductive fluid is retained within the reservoir when the movablecomponent or substance is in the first position; and the conductivefluid is released from the reservoir when the movable component orsubstance is in the second position.
 9. The shock sensor of claim 1,wherein the movable component or substance comprises a cantilever springand a magnet mounted to a first end of the cantilever spring.
 10. Theshock sensor of claim 9 further comprising a chamber, wherein: themagnet is not in contact with the chamber when the movable component orsubstance is in the first position; and the magnet is in contact withthe wall when the movable component or substance is in the secondposition.
 11. The shock sensor of claim 1, wherein shock sensor isconfigured to be reset after the shock event.
 12. The shock sensor ofclaim 11, wherein the movable component or substance is placed in thefirst position to reset the shock sensor.
 13. The shock sensor of claim1, wherein the shock sensor is configured to be soldered to the circuitboard of an electronic device.
 14. A shock sensor that actively andpassively indicates the occurrence of a shock event, comprising: achamber; first and second contacts extending into the chamber; andconductive fluid enclosed within the chamber, wherein the conductivefluid is configured to short the first and second contacts in responseto a shock event.
 15. The shock sensor of claim 14, wherein the shockevent exceeds an impact threshold level for the shock sensor.
 16. Theshock sensor of claim 14, wherein the first and second contacts arespaced a predetermined distance apart.
 17. The shock sensor of claim 14,wherein the first and second contacts are inserted in the chamber whilepreventing the conductive fluid from escaping the chamber.
 18. The shocksensor of claim 14, further comprising a reservoir containing theconductive fluid, wherein the reservoir is enclosed in the chamber. 19.The shock sensor of claim 18, further comprising a membrane configuredto maintain the conductive fluid within the reservoir, the membraneconfigured to rupture in response to the shock event.
 20. The shocksensor of claim 14, further comprising detection circuitry configured toprovide an electrical signal in response to the conductive fluidshorting the first and second contacts to actively detect a shock event.21. The method of claim 20, wherein the electrical signal is configuredto modify the state of the shock sensor.
 22. The method of claim 20,wherein the detection circuitry is configured to provide the electricalsignal continuously.
 23. The shock sensor of claim 14, wherein theconductive fluid is colored for ease of observation for passive shockdetection.
 24. The shock sensor of claim 14, wherein at least part ofthe chamber is translucent.
 25. The shock sensor of claim 14, whereinthe shock sensor is configured to be soldered to the circuit board of anelectronic device.
 26. A shock sensor, comprising: an electrical signalconductive and magnetically attractive shock detecting chamber; acantilever spring having a first end fixed to a support structure and asecond end disposed within the chamber; and a magnet fixed to the secondend of the cantilever spring, the magnet operative to be magneticallyattached to the chamber in response to a shock event.
 27. The shocksensor of claim 26, wherein the chamber is constructed from a magneticmetal.
 28. The shock sensor of claim 26, further comprising: a firstshock detection contact electrically coupled to the cantilever spring;and a second shock detection contact electrically coupled to thechamber.
 29. The shock sensor of claim 28, wherein the magnet isoperative to short the first and second shock detection contacts inresponse to the shock event.
 30. The shock sensor of claim 29, operativeto provide active shock detection.
 31. The shock sensor of claim 26,wherein the magnet remains in contact with the chamber in response tothe shock event to provide passive shock detection.
 32. The shock sensorof claim 26, wherein shock sensor is configured to be reset after theshock event.
 33. The shock sensor of claim 32, wherein the magnet isdetached from the chamber to reset the shock sensor.
 34. The shocksensor of claim 26, wherein the shock sensor is configured to besoldered to the circuit board of an electronic device.
 35. A method foractively and passively indicating the occurrence of a shock event usinga single shock sensor, comprising: providing active indication ofwhether the shock sensor endured a shock event; and providing passiveindication of whether the shock sensor endured the shock event.
 36. Themethod of claim 35, the method further comprising: moving a movablecomponent or substance from a first position to a second position;wherein providing active indication further comprises further comprisesproviding an electrical signal indicative of the occurrence of the shockevent in response to the movable component or substance being in thesecond position; and wherein providing passive indication furthercomprises observing the movable component or substance in the secondposition.
 37. The method of claim 36, wherein the movable component orsubstance comprises a chamber and a reservoir enclosed within thechamber.
 38. The method of claim 37, further comprising: retainingconductive fluid within the reservoir when the movable component orsubstance is in the first position; and releasing the conductive fluidfrom the reservoir in response to the shock event.
 39. The method ofclaim 36, wherein the movable component or substance comprises acantilever spring and a magnet mounted to a first end of the cantileverspring.
 40. The method of claim 39, further comprising: maintaining themagnet away from the walls of a chamber enclosing the magnet when themovable component or substance is in the first position; and placing themagnet in contact with the chamber in response to the shock event. 41.The method of claim 36, further comprising modifying the state of anelectronic device in response to providing the electrical signal.
 42. Asystem for actively and passively indicating the occurrence of a shockevent, comprising: an electronic device; and a shock sensor implementedin the electronic device, wherein the shock sensor further comprises: atleast one shock detection contact coupled to shock detection circuitryto form an open electrical circuit; and a movable component or substanceconfigured to move from a first position to a second position wherein,in response to a shock event, the movable component or substance movesto the second position and shorts the electrical circuit to provideactive shock detection and is observed in the second position to providepassive shock detection.
 43. The system of claim 42, wherein the shockdetection circuitry is configured to provide an electrical signal inresponse to the shorting of the electrical circuit.
 44. The system ofclaim 43, further comprising a diagnostic device configured to detectthe electrical signal.
 45. The system of claim 43, wherein theelectronic device further comprises a processor configured to change thestate of the electronic device in response to detecting the electronicsignal.
 46. The system of claim 45, wherein the electronic devicefurther comprises a storage device configured to store the change ofstate of the electronic signal.
 47. The system of claim 43, furthercomprising a RFID tag that is rendered operative to emit a signal whenthe electrical signal is detected.
 48. The system of claim 42, whereinthe movable component or substance is returned to the first position toreset the shock sensor.
 49. The system of claim 42, wherein the shocksensor is configured to be soldered to a component of the electronicdevice.
 50. The system of claim 49, wherein the component of theelectronic device is a circuit board.